Community help sought to clear Murray River’s giant sand slug

The coarse sand deposit – estimated to be enough to fill the MCG 13 times over – was discovered last year after flows were significantly reduced in the Barmah Choke, a narrow section of the river surrounded by the Barmah-Millewah Forest.

The area is unusual in that water tends to flow out of the Murray River across flat land rather than into it.

“This means that when the water flows out into the forest it leaves the sand behind, gradually filling the river channel,” the authority said.

“The accumulation of sand in the river is significant and increases as the river flows through the forest. 

“At the upstream end of the river about an eighth of the river is filled with sand – at the Edward Koelty offtake this increases to about a third.”

According to the authority, the century-old sand slug is speeding up riverbank erosion, filling deep pools and covering up snags.

“We're confident there's no silver bullet solution to this problem,” it said. 

“Instead, a multi-pronged approach looks to be the most promising option, including protecting key sections of riverbanks, removing sand in targeted areas, and moving water around the reach to reduce summer and autumn flow rates. 

“These all need to be investigated further to determine how, when and where each of these options could be applied,” the authority said.

Talks so far on how to solve the problem have centred on First Nations, irrigators, local government, state water authorities, and environmental and national park agencies.

The authority plans to have a list of management options ready by the end of this year, with about another year needed before those with a vested interest in removing the sand slug can start acting on the selected options.